This invention relates to a film peeling technique, and more particularly to a technique which can be effectively employed to peel a protective film from the substrate.
In a printed circuit board used in an electronic device such as a computer, a predetermined circuit is formed with copper on one or both sides of an insulated substrate.
A printed circuit board of this type can be manufactured as follows: First, a laminate consisting of a photosensitive resin (photo-resist) layer and a translucent resin film (protective film) for protecting the photosensitive resin layer is thermally formed on the conductive layer of the insulated substrate under pressure. Thereafter, a circuit pattern film is laid over the laminate thus formed, and the photosensitive resin layer is exposed to light through the circuit pattern film and the translucent resin film for a predetermined period of time. After the translucent resin film is peeled off, the photosensitive resin layer thus exposed to light is subjected to developing to form an etching mask pattern. Thereafter, the unnecessary parts of the conductive layer are removed by etching, to obtain a printed circuit board having the predetermined circuit pattern.
In the above-described printed circuit board manufacturing method, in developing the photosensitive resin layer it is necessary to peel the translucent resin film off. The film peeling operation is manually carried out. As the film is considerably thin, the printed circuit board may be damaged or broken if the force of peeling the film off is not uniform. That is, the person peeling the film off must be dextrous with his or her fingers and skillful.
Accordingly, it takes a relatively long time to peel the translucent resin film off, and therefore the time required for manufacturing the printed circuit board is increased by that long amount of time.